code: def rule2text(ctx):
      stream = ctx.start.getInputStream()
      # starting index of starting token
      startIdx = ctx.start.start
      # stopping index of stopping token
      stopIdx = ctx.stop.stop
  
      return stream.getText(startIdx, stopIdx)
  
imports: from importlib.metadata import version
  import sympy
  from sympy.external import import_module
  from sympy.printing.str import StrPrinter
  from sympy.physics.quantum.state import Bra, Ket
  from .errors import LaTeXParsingError
label_desc: Use image node_id 13 for calling a global function with example usage: rule2text(ctx) and returns: stream